(a) Field of the Invention
The present invention relates to a semiconductor device and, in particular, to a semiconductor device having a fine (small or narrow diameter) contact hole and a method for fabricating the fine contact hole.
(b) Description of the Related Art
As computers are widely spread for personal use, the semiconductor devices in computers are required to operate at high speed and to have high storage capability. In order to satisfy these requirements, semiconductor device fabrication technology has been developed so as to improve the device integration and density (e.g., reduce structure dimensions), operation reliability, and response time. To improve the device integration and/or density, it is required to form fine contact holes in various dielectric layers in the device.
The contact hole is formed such that a contact or via fills the contact hole with a conductive material for making an electrical connection between an electrode (e.g., a transistor terminal) and a wiring layer or between upper and lower (e.g., adjacent) wiring layers. In order to form a fine contact hole, it has been proposed to use a light source having relatively short wavelength, such as light from a KrF source, which recently has been used to form the contact hole during a lithography process for fabricating semiconductor devices using 0.13 μm or narrower linewidth technology.
The typical contact hole fabrication using photolithography is carried out in a sequential order of forming a dielectric layer on a semiconductor substrate, forming an anti-reflective coating (“ARC”) on the dielectric layer, forming a photoresist layer on the anti-reflective coating, and then forming a hole pattern on the photoresist layer through the photolithography process (e.g., selective irradiation of portions of the photoresist corresponding to the pattern with light, and development of the irradiated photoresist with one or more solvents).
However, it is difficult to form the hole pattern defining the contact hole in a width narrower than that of the design rule of a reticle used for photolithography. Accordingly, where the dielectric layer is selectively etched using the photoresist layer as a mask, there has been a limit to the minimum diameter of a fine contact hole fabricated using a conventional photolithography process.
U.S. Pat. Nos. 6,214,524 and 6,664,031 disclose contact hole fabrication methods using amine processes. However, these contact hole fabrication methods may also have limitations in forming a fine contact hole having a width narrower than that of the design rule of the reticle, as in the typical contact hole fabrication technique.